OBJECTIVES: To further understanding of the nutritional transition process by studying possible changes over time in the nutritional status of the Triqui ethnic group in the state of Oaxaca, Mexico. METHODS: A retrospective study was conducted using anthropometric data available from three prior studies (end of the 19th century, 1940, and 2002). Means and z scores for height, weight, and body mass index of Triqui adults were calculated using Frisancho reference data. Statistical analyses of the results were performed with Student's t and chi-square tests. Sociocultural information was collected through interviews and direct observations, as well as from the available literature. RESULTS: The height of Triqui adults has remained very low. A majority of Triqui women were found to be short or very short; this, coupled with the low level of education and high rates of illiteracy and monolingualism, is indicative of a culture that does not favor females. The appearance of overweight and obesity among the men studied in 2002, relative to those studied in 1940, is cause for concern. Overweight was also recorded among the women in 2002. CONCLUSIONS: Despite the limitations shared by all retrospective studies, these results confirm that the nutritional status of the Triquis is different now from what it was 60 years ago and that these changes are related to the cultural changes the group is experiencing. To further understand this epidemiologic phenomenon, where malnutrition and obesity coexist, cross-disciplinary studies are needed to analyze the biological, social, and cultural factors involved, so that culturally-appropriate measures can be adopted.